Anodes for electrowinning of manganese



1956 M. c. CAROSELLA 2,766,198

ANODEIS FOR ELECTROWINNING OF MANGANESE Filed March 5, 1953 Anode Rod Diaphragm INVENTOR MICHAEL C. CAROSELLA ANODE 1 6R ELECTROW MANGANESE Application March 5, 1953, Serial No. 340,556

1 Claim. (or. 204-105) 1 G OF The present invention relates to the electrowinning of manganese from aqueous manganese-bearing solutions and, more particularly, to the construction of anodes for use in such electrowinning process.

Heretofore, it has been discovered that it is beneficial, in the electrowinning of manganese from aqueous solutions, to employ anodes formed of 99% lead-1% silver alloy. Griginally, when this alloy was employed in sheet form as an anode, it was found that corrosion by the anolyte posed a serious problem. In an effort to solve this corrosion problem, portions of these anode sheets were removed by punching many circular or rectangular holes in the sheets. This resulted in an anode sheet having a lattice-like structure and, although these structures reduced the corrosion rate, they were found to encourage a non-uniform corrosion due to the concentration of current i'low around the removed portions of the anode sheet.

it is, therefore, the main object of the present invention to provide anodes suitable for the electrowinning of manganese which corrode uniformly, but which, at the same tin e, have a relatively high corrosion resistance.

Other aims and objects of the present invention will be apparent f om the following description and the appended claim.

In the drawing:

Figure l is a perspective view of an anode in accordance with the present invention;

Figure 2 is a. horizontal cross-sectional view of the two anodes in accordance with the present invention positioned on opposite sides of a cathode and separated therefrom by diaphragms, as would be the arrangement in a cell for the electrowinning of manganese from aqueous solutions.

in accordance with the present invention, anodes are provided (of approximately 99% lead-1% silver alloy) in the form of a plurality of cylindrical rods 1 positioned substantially equidistant from each other and having their longitudinal axes parallel and in the same plane. Joining the tops of the plurality of rod-shaped elements 1 is an electrically conductive crosspiece 2 which serves to connect all rods electrically and to hold them firmly in place, as is shown in Fig. l of the drawing.

It has been discovered that when employing anodes in accordance with the present invention the anode cur- ?i tes Pate 2,766,198 Patented Oct. 9, 1956 Table End Anode Anode Configuration Current, Oz. Wt. loss/ Density anode/Week amps/ft.

sheet 25 129. 0 lattice-like sheet 3. 7 plurality of rods 0. 86

From this table it can readily be seen that by employing the anode of the present invention a higher anode current density and correspondingly lower corrosion rate is obtainable.

Anodes in accordance with the present invention have shown a much longer useful life by reason of their lower corrosion rate and uniformity of corrosion.

What is claimed is:

In a process for the electrowinning of manganese from an aqueous solution containing a manganese salt, the steps comprising providing in a cell a plurality of alternate anolyte solutions and catholyte solutions separated by solution-permeable diaphragms; employing cathode sheets in each of the catholyte compartments; employing in each anolyte compartment an anode comprising a plurality of substantially cylindrical rods having their longitudinal axes parallel and coplanar, said anode rods being composed of approximately 99% lead-1% silver alloy; and applying a voltage between each of said cathodes and said anodes to deposit metallic manganese at said cathodes at high current densities and reduced anode corrosion.

References Cited in the file of this patent UNITED STATES PATENTS 903,939 Winsom Nov. 17, 1908 1,092,369 Kolsky Apr. 7, 1914 FOREIGN PATENTS 284 Great Britain Ian. 5, 1914 OTHER REFERENCES Bureau of Mines Bul. #463 (1946), pp. 60, 61 to 68 and Fig. 31 (facing p. 63).

Fink et al.: Transactions of the American Electrochemical Society, vol. 46 (1924), pp. 349 to 357. 

